Spatial Mapping of Potential Biochar Effects on Agricultural Water Use and Crop Yield and Associated Cost-Benefit Analysis

While a large body of literature exists on the ability of biochar to retain water and nutrients, little research exists regarding where and for which crops biochar could produce the greatest water retention and crop yield results. Biochar benefits depend strongly on the type of soil and crops in question, which vary across the United States. Therefore, geographic biochar research is important because it can indicate where biochar usage is most efficient, and guide scholars and biochar stakeholders to study and invest in the product accordingly. Our study seeks to provide this geographic data and help fill this gap in biochar research. Using US Department of Agriculture's Farm and Ranch Irrigation Surveying (FRIS) information, US Geological Survey national water use data, North American Carbon Program (NACP) soil mapping, and existing biochar lab studies, we are conducting a meta-analysis study in which these data are combined to spatially map potential water retention and crop yield benefits from biochar usage. Then, using irrigation expense data generated by FRIS, we are conducting a partial equilibrium cost-benefit analysis, considering predicted biochar application costs versus avoided water costs and additional crop yield profit. This analysis is mapped to display where in the United States biochar application, and thus advertising and production, would be most profitable and practical in these dimensions. Early results of this study suggest that western states as a whole are poised to benefit more from biochar's water retention properties. In addition, certain crops show much larger potential yield benefits from biochar addition than others. If borne out, these results suggest that certain regions have much larger gains in the cost-benefit analysis and can thus be targeted in future studies. Spatially mapping predicted biochar effects on water retention and crop yield increase, and mapping expected financial benefits or losses, allows visual analysis of biochar benefits across the country. These results are useful for scholars, agricultural extensions, and policymakers in proposing field experiments, targeting farmers, and proposing incentives for biochar use in the future.